EUVE Spectra of Jupiter and Io Torus

EUVE SPECTRA OF JUPITER AND THE IO TORUS

NASA's Extreme Ultraviolet Explorer (EUVE) satellite
has obtained spectra of Jupiter and the Io torus
before and during the impacts of comet SL-9.

The Jupiter spectrum in the upper panel shows strong
helium emissions during the impacts that were
not present immediately before the impacts began.
The strongest emission is at 58.4 nm. An additional
feature at 50.4 nm indicates that the emissions may
result from recombination of helium ions. The presence
of these emissions imply that substantial amounts of
helium and/or helium ions have been lifted to high
altitudes in Jupiter's upper atmosphere. Other features
in the spectrum are currently unidentified.

The Io torus spectrum in the lower panel shows many
emissions of sulfur, oxygen, and even sodium ions
at wavelengths between 35 and 75 nm. At the present
time we see no indications of substantial changes
in the torus extreme ultraviolet emissions.
The torus may respond to the impacts on a longer
timescale, and EUVE will be monitoring Jupiter and
the Io torus until the beginning of August to look
for any changes in the system.